Digital predistortion linearization for power amplifiers

An RF transmitter module for a cellular radio, said transmitter module comprising:

• a digital signal processer (DSP) providing a digital signal to be transmitted, said DSP being implemented in CMOS;
• a digital-to-analog converter (DAC) responsive to the digital signal from the DSP and a clock signal from a clock circuit, said DAC converting the digital signal to an analog signal;
• a tunable bandpass filter responsive to the analog signal from the DAC and removing frequencies in the analog signal outside of a frequency band of interest;
• a power amplifier responsive to the filtered analog signal from the bandpass filter and amplifying the analog signal;
• and
• a calibration feedback device responsive to the amplified analog signal and providing a feedback signal to the DSP, wherein the DSP provides pre-distortion of the digital signal to compensate for non-linearities of the power amplifier using the feedback signal.

An RF transmitter module for a cellular vehicle radio, said transmitter module comprising:

• a digital signal processor (DSP) providing a digital signal to be transmitted;
• a digital-to-analog converter (DAC) responsive to the digital signal from the DSP and converting the digital signal to an analog signal;
• a tunable bandpass filter responsive to the analog signal from the DAC and removing frequencies in the analog signal outside of a frequency band of interest;
• a power amplifier responsive to the filtered analog signal from the bandpass filter and amplifying the analog signal;
• and
• a calibration feedback device responsive to the amplified analog signal and providing a feedback signal to the DSP, wherein the DSP provides pre-distortion of the digital signal to compensate for non-linearties of the power amplifier using the feedback signal, employs a noise-shaping operation to shape the analog signal from the DAC to remove quantization noise in an immediate vicinity of the analog signal so as to improve signal-to-noise ratio, and performs an infinite impulse response process to lower a noise floor in the vicinity of the analog signal.